Massey Ferguson 04.01.44 – Transmission Control Module (TRANS): Issue With Signal From Transmission Mounted Engine Speed Sensor (TRANS)

The control module is receiving an erratic signal, an out-of-range signal, or no signal at all from the engine speed (RPM) sensor mounted on the transmission housing, which often forces the tractor into a restricted auxiliary or emergency limp mode.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7700 Series
• 7700S Series

1. 1

   Inspect the wiring harness between the transmission-mounted speed sensor and the TRANS module for chafing, breaks, or melted insulation.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, moisture, or poor terminal tension.

3. 3

   Verify the sensor's 12V power supply by checking the associated transmission control fuses (often designated as A013, fuse 11, or fuse 33).

4. 4

   Remove the sensor and inspect the magnetic tip for metallic shavings that can distort the Hall-effect signal. Clean the tip to see if it temporarily resolves the issue before replacing parts.

1. 1

   Locate the Sensor

   Identify the engine speed sensor mounted on the transmission housing (typically located on the bell housing/flywheel housing where it reads the input shaft/crankshaft position).

2. 2

   Disconnect Battery

   Disconnect the negative battery terminal to prevent electrical spikes.

3. 3

   Remove the Sensor

   Unplug the electrical connector. Remove the retaining bolt holding the sensor to the housing. Carefully twist and pull the sensor out.

4. 4

   Clean the Port

   Wipe the mounting surface and port clean, ensuring no dirt or old O-ring material falls into the transmission housing.

5. 5

   Install the New Sensor

   Lubricate the O-ring on the new sensor with a small amount of clean transmission fluid. Push the sensor into the port until it seats fully.

6. 6

   Secure and Reconnect

   Install and tighten the retaining bolt. Reconnect the wiring harness, ensuring it clicks into place.

7. 7

   Clear Codes

   Reconnect the battery. Use a diagnostic scan tool to clear the 04.01.44 fault code from the TRANS module, then start the tractor and verify that the engine RPM registers correctly on the dash and the transmission shifts normally.